Off-highway work vehicles, such as tractors, have been developed for a myriad of different purposes and are generally known to include a drivetrain sufficient to deliver a high amount of power and torque to one or more drive wheels. Typical drivetrains for a work vehicle include an engine, a transmission or gearbox, and a final drive reduction assembly. The final drive reduction assembly includes a bar axle that functions to transfer the rotational power generated by the drivetrain to the drive wheel(s), which is typically accomplished using a hub configured to establish a connection between the bar axle and the drive wheel(s).
The bar axle and hub connection may additionally include an intermediate casing to facilitate an attachment between the two parts. The casing typically includes a cylindrical opening corresponding in size and shape to the bar axle and a tapered outer surface. The tapered outer surface is received within an opening of the hub and creates a friction joint with a tapered inner surface of the hub. The casing may be pressed into and attached to the hub using a plurality of bolts. Such a configuration additionally creates a friction joint between the casing and the bar axle.
The friction joints allow for rotational force to be transferred from the axle through the casing, through the hub, and to the drive wheel(s). In order to increase the amount of rotational force that may be transferred, keys may be positioned in respective keyways defined between the bar axle and the hub, and between the hub and the casing. With respect to the friction joint between the casing and the hub, the keyway is known to be defined in a direction parallel to the tapered surfaces of the hub and casing. However, certain problems may exist with such a configuration. For example, with such a configuration, a cross-sectional thickness of the casing below the keyway may not be sufficient to transfer a desired amount of rotational force or torque to the hub from the bar axle. Additionally, such a configuration may be susceptible to a yielding of the keyway walls.
Accordingly, a keyway configuration for the casing designed to withstand an increased amount of force without yielding would be useful.